Test: Endomembrane System & Mitochondria - NEET MCQ

In mitochondria, the inner membrane space is filled with a matrix which contains dense granules  along  with  ribosomes  and mitochondrial DNA. The mitochondrial DNA is circular in nature. There number varies from 2-6. Besides DNA, a mitochondrion has RNA and its ribosomes also. Thus, a complete protein synthesizing machinery is present in mitochondria, which suggests  the semi-autonomous nature of mitochondria. Dictyosome, lysosome and peroxisome do not have their own DNA.

Topic in NCERT: Mitochondria

Line in NCERT: "the matrix also possesses single circular DNA molecule, a few RNA molecules, ribosomes (70S) and the components required for the synthesis of proteins."

Correct Answer :- c

Explanation : Chloroplasts are structurally made up of two components- thylakoids (internal membrane structures) and stroma. Some of the thylakoid membranes are stacked one above the other and are called as grana. The grana contain light trapping pigment chlorophyll and are thus the site of light reaction.

Topic in NCERT: Chloroplast structure

Line in NCERT: "Chlorophyll pigments are present in the thylakoids."

Carbohydrates are organic compounds synthesized in the chlorophyll containing cells of some bacteria,-algae and green plant cells, during photosynthesis. Certain photoautotrophic bacteria eg. Green sulphur bacteria and purple sulphur bacteria contain pigments like chlorobium chlorophyll and bacteriochlorophyll respectively that helps them in photosynthesis. During photosynthesis carbon dioxide is reduced into carbohydrates by water and oxygen is liberated.

The membrane around the vacuole is called the tonoplast.
Explanation:
The tonoplast is a specialized membrane that surrounds the vacuole in plant cells. It is responsible for maintaining the integrity and stability of the vacuole and controlling the movement of molecules in and out of the vacuole.
Key points:
- The tonoplast is a membrane that surrounds the vacuole in plant cells.
- It is responsible for maintaining the integrity and stability of the vacuole.
- The tonoplast controls the movement of molecules in and out of the vacuole.
- The tonoplast is essential for the storage of various substances in the vacuole, such as water, ions, sugars, and pigments.
- The tonoplast also plays a role in regulating the pH and osmotic balance within the vacuole.
- The tonoplast is composed of lipids and proteins that form a selectively permeable barrier.
- The tonoplast is involved in various cellular processes, including nutrient storage, waste disposal, and cell expansion.
- The tonoplast is a vital component of plant cell structure and function.

Topic in NCERT: Vacuoles

Line in NCERT: "The vacuole is bound by a single membrane called tonoplast."

Oxysomes are the structure present in the inner surface of mitochondra.it is also known as f0-f1particle or Atp synthese.oxysomes play an important role in formation energy for the functioning of the cell.oxysome help in the electron transport i.e oxidation and reduction rxn in respiration.

Topic in NCERT: Mitochondria

Line in NCERT: "Each mitochondrion is a double membrane-bound structure with the outer membrane and the inner membrane dividing its lumen distinctly into two aqueous compartments, i.e., the outer compartment and the inner compartment. The inner membrane forms a number of infoldings called the cristae (sing.: crista) towards the matrix."

Explanation:
The correct answer is Lysosomes. Lysosomes are cell organelles that store hydrolytic enzymes. Here's a detailed explanation:
- Chloroplasts: Chloroplasts are organelles found in plant cells that are responsible for photosynthesis. They contain chlorophyll and are involved in the conversion of sunlight into chemical energy. They do not store hydrolytic enzymes.
- Centrioles: Centrioles are small cylindrical structures found in animal cells. They play a role in cell division and the formation of the spindle apparatus. They do not store hydrolytic enzymes.
- Chromoplasts: Chromoplasts are organelles found in plant cells that are responsible for the synthesis and storage of pigments other than chlorophyll. They do not store hydrolytic enzymes.
- Lysosomes: Lysosomes are membrane-bound organelles that contain various hydrolytic enzymes. These enzymes are involved in the breakdown of macromolecules, such as proteins, nucleic acids, carbohydrates, and lipids. Lysosomes are involved in processes such as digestion, recycling of cellular components, and defense against pathogens.
In summary, lysosomes are the cell organelles that store hydrolytic enzymes.

Topic in NCERT: Lysosomes

Line in NCERT: "Lysosomes are single membrane structures containing enzymes for digestion of all types of macromolecules."

The empirical formula of chlorophyll molecule is C₅₅H₇₂O_5N4Mg. It has tadpole like configuration. It is consisted of a porphyrin head and a phytol tail. Porphyrin is a cyclic tetrapyrol structure, having a magnesium atom in the centre. Chlorophyll a methyl group (CH₃₎ is attached to the third carbon in the porphyrin head.

Topic in NCERT: Plastids

Line in NCERT: "Chloroplasts, which contain chlorophyll"

Cristae is the inner membrane foldings in mitochondria. It is the finger-like projection of the inner mitochondrial membrane provide the site for ATP synthesis.

Topic in NCERT: Mitochondria

Line in NCERT: "The inner membrane forms a number of infoldings called the cristae (sing.: crista) towards the matrix."

In the matrix of mitochondria:
- Ribosomes: Present to help in protein synthesis.
- RNA: Various types of RNA are found, aiding in different cellular processes.
- DNA: Mitochondrial DNA is located here, crucial for mitochondrial function.
- All of the above: Correct, as all these components are integral to mitochondrial structure and function, contributing to energy production and cellular processes.

Topic in NCERT: Mitochondria

Line in NCERT: "The matrix also possesses single circular DNA molecule, a few RNA molecules, ribosomes (70S) and the components required for the synthesis of proteins."